> We'd end up with very many properties, though. And long discussions about
> which properties/values to duplicate: background-position?
> caption-side? clear? float? text-align? vertical-align?
These are always logical. You can't render physical-left-aligned text in vertical text flow, can you. So we don't need corresponding logical properties for them.
> top? right? > bottom? left?
They need corresponding logical properties, and current idea is to call them as offset-before, offset-after, etc.
The number of additional properties, including offset-*, is 34, given all properties from CSS 2.1 and CSS3 that are CR or above. The draft is almost ready to propose.
> The pseudo-class and media queries options are compelling to me as they
> allow optimized values to be set, not just mirrored values. In general,
> I don't think you can just mirrors values. For example, in the textbook
> example above you may want to have different borders on right and left pages.
> Using media queries, one could e.g. express this
> as:
>
> @media (page: right) {
> border: thin solid red;
> }
> @media (page: left) {
> border: thin solid blue;
> }
I'm not opposed to the idea. Actually, it's really brilliant when you want different styles per direction as you said.
But it's a little overkill if you want logically-same style per direction; you're forced to duplicate logically-same properties. And more than 90% of cases for horizontal/vertical are logically-same styles. It'd be perfect if, in addition to your proposal, there's a help for the most common case in horizontal/vertical. Could you help us to figure out how we can write it simpler for the vertical flow?
> > Another idea: just specify writing-mode in HTML instead and don't >
> have it be in CSS at all (except as a pseudo class you match on in > order
> to provide rules for that writing mode). This is a little > weird in that
> we already have direction in CSS though.
>
> I think it makes sense for this to be known in HTML.
I'm not sure if I understand this sentence correctly due to my English skill, I'm sorry in advance if I misunderstand, but I just want you to understand that writing-mode is a stylistic property. It is under "Format" menu in word processors. I understand thinking it as stylistic property is sometimes hardly acceptable, as it took months for the English-speaking people to understand this when I tried before, but it is from the definition of East Asians.
As far as I understand, you don't want writing-mode to be defined in HTML if it's purely a stylistic property, right?
Regards,
Koji